The present invention relates generally to agricultural balers and more particularly to a method and apparatus for calibrating the bale size indicator on a round baler.
Round balers have become quite prevalent for their capability of producing a conveniently sized cylindrical bale and very often include a mechanism to wrap the bale before it is ejected from the machine. Such round balers generally have a bale-forming chamber defined by an array of side-by-side belts, transverse slats trained on chains, a plurality of rolls or a combination of these various elements, e.g., rolls and belts. Crop material, such as hay, is picked up from the ground as the baler travels across the field, and is fed into a fixed or expandable chamber where it is rolled up to form a compact cylindrical hay package. While still inside the bale-forming chamber in its compacted form, the outer surface of the package is wrapped with twine or other wrapping material, such as film or net, prior to ejection of the wrapped bale from the chamber onto the ground for subsequent handling.
Continuous pressures to increase operational efficiency and ease of operation in round balers have resulted in increased levels of automation. Sensors monitoring bale chamber configuration (size) and wrapper usage are common. One automation area of interest involves monitoring of the size and shape of the bale in the bale-forming in order to initiate wrapping and bale ejection operations or alert the operator to take such actions. Currently, new balers or balers having just been serviced must have bale size indicators calibrated by manual means. This process typically involving measuring the diameter of a bale formed in the in the chamber after ejection. The bale diameter is used to correlate the measured bale diameter with the sensed bale diameter, typically in a sensor control or interface apparatus.
It would be desirable to provide an apparatus and a method for automatically calibrating the bale size indicator in a round baler which eliminates the need to manually measure the diameter of a completed bale after ejection and then manually entering that measurement into the size indicator apparatus. Additional advantages would be realized by an apparatus capable of using sensors and monitoring devices already existing on the baler in order to perform the calibration operation.